Latin music in the United States is defined by both the Recording Industry Association of America (RIAA) and Billboard magazine as any release with 51% or more of its content recorded in Spanish. The best performing Latin songs in the United States have been compiled by Billboard since September 1986. The magazine had already a major overall songs chart titled Hot 100 since August 1958. Since 2007, the chart has tracked digital sales, streaming figures and radio airplay. Prior to that, the Hot 100 only measured the latter format.